9mm M&P barrel in a .40 S&W-a photo comparison-UPDATE IN OP-Range test

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9mm M&P barrel in a .40 S&W-a photo comparison-UPDATE IN OP-Range test (Page 1 of 7)

Dog1

U.S. Rifle, Caliber .30, M1

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Posted: 12/23/2010 2:56:26 PM EDT

[Last Edit: Dog1]

I ordered a factory M&P 9mm barrel for the fullsize from Brownell's this week. It came today. My plan was to see if it was dimnsionally the same as the 40 S&W, since the 9 and 40 M&P fullsizes are, essentially the same guns.

I took some measurements and some side by side photos-

The 9mm barrel locked up nice and tight, It was not loose or ill fitting in any way. I had called S&W and asked a tech guy about the dimensions of the 9mm and 40 slides. He said that dimensionally they are the same. Of course he went on to tell me that I should buy a dedicated 9mm and not use a different barrel...then he said quietly, wink, wink.

Then I broke out the digital calipers-

40 S&W barrel-

9mm barrel-

Next was a function test. Using the new barrel, my M&P40, some Tula 9mm from Wal-Mart and a 40 S&W mag-I have a 9mm mag on order from 44mag.com, it's just not here yet-I went to test it in my unofficial test range out back.

It functioned flawlessly, with one exception-right before the last round, the follower would engage the slide stop, not feeding the last round. That is due to the mags being for the larger diameter 40 round. The smaller 9mm round allowed the notch in the follower to hit the slide lock before chamering the last round.

I expect that to be solved with a factory 9mm mag. I would have had a magazine had any of the local shops had one in stock yesterday, when I was in town.

I will test it again when the new mag arrives.

Here is the schematic to the M&P from Brownell's-
http://www.brownells.com/.aspx/pid=0/sid=859/schematicsdetail/MP__Semi_Auto_

As you can see, the 9/40/357 guns share the common parts, with the exception of the barrels. 40/357 has it's mag and 9mm has it's mag.

A 40S&W barrel will not fit in a 9mm M&P. It's only one way..a 40 to 9.

UPDATE 01/03/2011-

Went to the range today for a test. I traveled to Louisville, KY to shoot at the an door range-Bluegrass Indoor Range located at 4402 Kiln Court Louisville, KY 40218 (502) 451-9088. Great bunch of guys there and the prices are affordable.

I took 200 rounds of 115gr 9mm. 150 of it was Tula, not know for being all that clean and 50 rounds of Federal Champion.

Distance was 21 feet. Course of fire was slow, double taps and rapid-as fast as the range rules allowed.

No failures to feed or eject, one failure to fire and I blame that on a hard primer-it was the Tula ammo. There was a noticeable dent from the firing pin. I reset the sear and it did fire the second time.

The Tula was nasty..very dirty. The Federal Champion had a huge fireball. The Tula did not.

All and all, I'm happy with the test and now have 2 guns in one.

Hansan: "This is a .30 caliber, gas operated, clip fed, semi-automatic rifle....."
Soldier: "Look, you ain't sellin it to me, you're only showing me how it works."

dirtyone04

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Joined Jan 2009
Posts 479
EE 100% (120)

OH, USA

Posted: 12/23/2010 3:12:59 PM EDT

[#1]

http://www.ar15.com/forums/topic.html?b=5&f=16&t=101824
This is a post I had a few days ago. Same topic.
I did the same thing to my M&P 40c. I did all the measurements and then bought the 9c barrell from brownells as well. It doesn't work the other way around, though. You can't put a 40 barrell in a 9. Has to do with the ramping at the front of the chamber on the 40. I did have the 9 mags to test it and it ran without a hitch.

Anger is a Gift

Dog1

U.S. Rifle, Caliber .30, M1

Joined May 2001
Posts 23613
EE 100% (488)

IN, USA

Posted: 12/23/2010 3:15:39 PM EDT

[#2]

Originally Posted By dirtyone04:
http://www.ar15.com/forums/topic.html?b=5&f=16&t=101824
This is a post I had a few days ago. Same topic.
I did the same thing to my M&P 40c. I did all the measurements and then bought the 9c barrell from brownells as well. It doesn't work the other way around, though. You can't put a 40 barrell in a 9. Has to do with the ramping at the front of the chamber on the 40. I did have the 9 mags to test it and it ran without a hitch.

I remember your post. I have had a few IM's asking me the same question and in fact I had this same discussion with Scott at Apex a while back.

I thought that a photo comparison would help some of the guys wondering if they could do it.

I was not trying to step on your toes....

Hansan: "This is a .30 caliber, gas operated, clip fed, semi-automatic rifle....."
Soldier: "Look, you ain't sellin it to me, you're only showing me how it works."

dirtyone04 Member Joined Jan 2009 Posts 482 EE 100% (120) OH, USA	Posted: 12/23/2010 5:04:26 PM EDT [#3] I don't feel that way at all. I just wanted you to know my experience. It's nice to have one weapon that can function as two.
	Anger is a Gift

Dog1 U.S. Rifle, Caliber .30, M1 Joined May 2001 Posts 23622 EE 100% (488) IN, USA	Posted: 12/23/2010 5:30:31 PM EDT [#4] Originally Posted By dirtyone04: I don't feel that way at all. I just wanted you to know my experience. It's nice to have one weapon that can function as two. You it is...I was looking to buy a 9mm, but I figure why, if the barrel and mags will work and the barrel is a fraction of an aftermarket barrel.
	Hansan: "This is a .30 caliber, gas operated, clip fed, semi-automatic rifle....." Soldier: "Look, you ain't sellin it to me, you're only showing me how it works."

TEAMSHRALP Joined Nov 2009 Posts 788 EE 0% (0) WA, USA	Posted: 12/23/2010 6:17:24 PM EDT [#5] Could you go the other way? .40 barrel in a 9mm slide, and frame?

colklink

Member

Joined Dec 2001
Posts 18077
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WV, USA

Posted: 12/23/2010 6:36:19 PM EDT

[#6]

Originally Posted By TEAMSHRALP:
Could you go the other way? .40 barrel in a 9mm slide, and frame?

Originally Posted By dirtyone04:
http://www.ar15.com/forums/topic.html?b=5&f=16&t=101824
This is a post I had a few days ago. Same topic.
I did the same thing to my M&P 40c. I did all the measurements and then bought the 9c barrell from brownells as well. It doesn't work the other way around, though. You can't put a 40 barrell in a 9. Has to do with the ramping at the front of the chamber on the 40. I did have the 9 mags to test it and it ran without a hitch.

He answered that here.

As I am now an ordained minister in the universal life church feel free to contact me for your spiritual needs.

Dog1

U.S. Rifle, Caliber .30, M1

Joined May 2001
Posts 23623
EE 100% (488)

IN, USA

Posted: 12/23/2010 6:40:55 PM EDT

[#7]

Originally Posted By colklink:

Originally Posted By TEAMSHRALP:
Could you go the other way? .40 barrel in a 9mm slide, and frame?

Originally Posted By dirtyone04:
http://www.ar15.com/forums/topic.html?b=5&f=16&t=101824
This is a post I had a few days ago. Same topic.
I did the same thing to my M&P 40c. I did all the measurements and then bought the 9c barrell from brownells as well. It doesn't work the other way around, though. You can't put a 40 barrell in a 9. Has to do with the ramping at the front of the chamber on the 40. I did have the 9 mags to test it and it ran without a hitch.

He answered that here.

And I did too-

Originally Posted By Dog1:

A 40S&W barrel will not fit in a 9mm M&P. It's only one way..a 40 to 9.

Hansan: "This is a .30 caliber, gas operated, clip fed, semi-automatic rifle....."
Soldier: "Look, you ain't sellin it to me, you're only showing me how it works."

America-first Member Joined Oct 2005 Posts 18800 EE 0% (0) FL, USA	Posted: 12/23/2010 7:27:24 PM EDT [#8] One of the best threads ever; it deserves a stcky for certain.
	No single raindrop believes it is responsible for the flood.

badkarmaiii Those who can't DO, teach... Joined Feb 2009 Posts 1347 EE 0% (0) NM, USA	Posted: 12/24/2010 11:49:25 AM EDT [#9] It has been my experience doing this that the width of the barrel hood is what mandates starting with a 40 or 357 and converting down to a smaller caliber. There can be a little lateral play and the gun can still shoot accurately.
	Instructor and M&P & Glock Armorer, Personal Security Consulting: www.traintoprotect.com When seconds count, the police are only minutes away. Train to protect yourself!

DrMark Diet Mountain Dewaholic Joined Jun 2001 Posts 12376 EE 100% (5) VA, USA	Posted: 12/24/2010 12:40:05 PM EDT [#10] Great thread. I remember people doing this (40 ––> 9) with the SIG P229 when it came out several years ago. This is the first I've seen on the topic for the M&P.
	NRA Endowment Life Member RIP - John Dean "Jeff" Cooper RIP - Wayne Henry Cobb Jr. (Eric the Hun)

LifeSTAR Joined Mar 2009 Posts 588 EE 100% (1) USA	Posted: 12/24/2010 12:55:37 PM EDT [#11] so i guess this means 40 = 9mm?

Dog1

U.S. Rifle, Caliber .30, M1

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IN, USA

Posted: 12/24/2010 1:27:21 PM EDT

[#12]

Originally Posted By badkarmaiii:
It has been my experience doing this that the width of the barrel hood is what mandates starting with a 40 or 357 and converting down to a smaller caliber. There can be a little lateral play and the gun can still shoot accurately.

This is true..I was looking at it again today. I was hoping that my mag from 44mag.com would get here today, but alas, it did not make it.

I got out my feeler gauges and checked the side-to-side of the 40 barrel then the 9 barrel, just cause I'm bored.

The gap between the barrels and the slide are the same.

Hansan: "This is a .30 caliber, gas operated, clip fed, semi-automatic rifle....."
Soldier: "Look, you ain't sellin it to me, you're only showing me how it works."

ARJJ Rifleman Joined Sep 2006 Posts 4620 EE 100% (59) MS, USA	Posted: 12/24/2010 2:26:54 PM EDT [#13] Dog1, are the ejectors the same for both .40 and 9mm? I ask because I know Glocks have different ejectors for each caliber. I was wondering if the Smiths differ, too.
	STOP RESISTING! fla556guy: "When you have a shit-hole the answer is to flush it as fast as possible, not bathe in the shit."

Dog1 U.S. Rifle, Caliber .30, M1 Joined May 2001 Posts 23641 EE 100% (488) IN, USA	Posted: 12/24/2010 2:35:53 PM EDT [Last Edit: Dog1] [#14] Originally Posted By ARJJ: Dog1, are the ejectors the same for both .40 and 9mm? I ask because I know Glocks have different ejectors for each caliber. I was wondering if the Smiths differ, too. Yes, the ejectors are the same for the 9mm/.357Sig/.40S&W guns- http://www.brownells.com/.aspx/sid=49652/sku/Ejector
	Hansan: "This is a .30 caliber, gas operated, clip fed, semi-automatic rifle....." Soldier: "Look, you ain't sellin it to me, you're only showing me how it works."

ARJJ Rifleman Joined Sep 2006 Posts 4622 EE 100% (59) MS, USA	Posted: 12/24/2010 2:41:54 PM EDT [#15] Thanks, man! I was thinking of selling my .40 and buying a 9mm (just for the lower price of ammo). Looks like all I need is a new barrel! Does the 9mm use a different recoil spring, as well?
	STOP RESISTING! fla556guy: "When you have a shit-hole the answer is to flush it as fast as possible, not bathe in the shit."

Dog1 U.S. Rifle, Caliber .30, M1 Joined May 2001 Posts 23642 EE 100% (488) IN, USA	Posted: 12/24/2010 2:49:17 PM EDT [Last Edit: Dog1] [#16] Originally Posted By ARJJ: Thanks, man! I was thinking of selling my .40 and buying a 9mm (just for the lower price of ammo). Looks like all I need is a new barrel! Does the 9mm use a different recoil spring, as well? Yep, same recoil spring too. All you need is the barrel and mags.
	Hansan: "This is a .30 caliber, gas operated, clip fed, semi-automatic rifle....." Soldier: "Look, you ain't sellin it to me, you're only showing me how it works."

badkarmaiii

Those who can't DO, teach...

Joined Feb 2009
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Posted: 12/24/2010 2:58:14 PM EDT

[#17]

Originally Posted By Dog1:

Originally Posted By badkarmaiii:
It has been my experience doing this that the width of the barrel hood is what mandates starting with a 40 or 357 and converting down to a smaller caliber. There can be a little lateral play and the gun can still shoot accurately.

This is true..I was looking at it again today. I was hoping that my mag from 44mag.com would get here today, but alas, it did not make it.

I got out my feeler gauges and checked the side-to-side of the 40 barrel then the 9 barrel, just cause I'm bored.

The gap between the barrels and the slide are the same.

What about the barrel hoods? They're the portions of the barrels that protrude to the rear and have the cutout so see if the chamber is loaded. It would be ideal if they're identical, but 9mm barrels usually have hoods about .5mm narrower.

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When seconds count, the police are only minutes away. Train to protect yourself!

ARJJ Rifleman Joined Sep 2006 Posts 4623 EE 100% (59) MS, USA	Posted: 12/24/2010 3:03:12 PM EDT [#18] Awesome, Dog1! Looks like I can be shooting 9mm for about $80.
	STOP RESISTING! fla556guy: "When you have a shit-hole the answer is to flush it as fast as possible, not bathe in the shit."

dirtyone04 Member Joined Jan 2009 Posts 490 EE 100% (120) OH, USA	Posted: 12/24/2010 3:24:47 PM EDT [#19] Originally Posted By ARJJ: Awesome, Dog1! Looks like I can be shooting 9mm for about $80. Don't forget to pick up a few mags. I have the full size M&P 9 and the mags work fine. They just stick out a bit. I did pick up a few 9c mags from 44mag.com. One with the finger rest and one without. They had them the least expensive, but stock was low.
	Anger is a Gift

ARJJ

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Joined Sep 2006
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MS, USA

Posted: 12/24/2010 3:43:36 PM EDT

[#20]

Originally Posted By dirtyone04:

Originally Posted By ARJJ:
Awesome, Dog1!

Looks like I can be shooting 9mm for about $80.

Don't forget to pick up a few mags. I have the full size M&P 9 and the mags work fine. They just stick out a bit. I did pick up a few 9c mags from 44mag.com. One with the finger rest and one without. They had them the least expensive, but stock was low.

That's the kicker––I already have half a dozen .40 mags, and M&P mags aren't exactly inexpensive.

I think I'll look around on the EE.

STOP RESISTING!

fla556guy: "When you have a shit-hole the answer is to flush it as fast as possible, not bathe in the shit."

Dog1

U.S. Rifle, Caliber .30, M1

Joined May 2001
Posts 23643
EE 100% (488)

IN, USA

Posted: 12/24/2010 3:53:49 PM EDT

[#21]

Originally Posted By badkarmaiii:

Originally Posted By Dog1:

Originally Posted By badkarmaiii:
It has been my experience doing this that the width of the barrel hood is what mandates starting with a 40 or 357 and converting down to a smaller caliber. There can be a little lateral play and the gun can still shoot accurately.

This is true..I was looking at it again today. I was hoping that my mag from 44mag.com would get here today, but alas, it did not make it.

I got out my feeler gauges and checked the side-to-side of the 40 barrel then the 9 barrel, just cause I'm bored.

The gap between the barrels and the slide are the same.

What about the barrel hoods? They're the portions of the barrels that protrude to the rear and have the cutout so see if the chamber is loaded. It would be ideal if they're identical, but 9mm barrels usually have hoods about .5mm narrower.

I measured the hoods.

The 40 hood is .425 in width.

The 9mm is .396 in width.

The difference is .089.

Hansan: "This is a .30 caliber, gas operated, clip fed, semi-automatic rifle....."
Soldier: "Look, you ain't sellin it to me, you're only showing me how it works."

Dog1

U.S. Rifle, Caliber .30, M1

Joined May 2001
Posts 23644
EE 100% (488)

IN, USA

Posted: 12/24/2010 3:54:37 PM EDT

[Last Edit: Dog1] [#22]

Originally Posted By ARJJ:

Originally Posted By dirtyone04:

Originally Posted By ARJJ:
Awesome, Dog1!

Looks like I can be shooting 9mm for about $80.

Don't forget to pick up a few mags. I have the full size M&P 9 and the mags work fine. They just stick out a bit. I did pick up a few 9c mags from 44mag.com. One with the finger rest and one without. They had them the least expensive, but stock was low.

That's the kicker––I already have half a dozen .40 mags, and M&P mags aren't exactly inexpensive.

I think I'll look around on the EE.

Brand new mags, $21.99

http://www.44mag.com/product/m_p_9/smith_and_wesson

Best place for M&P mags.

Hansan: "This is a .30 caliber, gas operated, clip fed, semi-automatic rifle....."
Soldier: "Look, you ain't sellin it to me, you're only showing me how it works."

badkarmaiii Those who can't DO, teach... Joined Feb 2009 Posts 1349 EE 0% (0) NM, USA	Posted: 12/24/2010 5:44:27 PM EDT [#23] Thanks!
	Instructor and M&P & Glock Armorer, Personal Security Consulting: www.traintoprotect.com When seconds count, the police are only minutes away. Train to protect yourself!

Dog1 U.S. Rifle, Caliber .30, M1 Joined May 2001 Posts 23652 EE 100% (488) IN, USA	Posted: 12/24/2010 6:03:57 PM EDT [#24] Originally Posted By badkarmaiii: Thanks!
	Hansan: "This is a .30 caliber, gas operated, clip fed, semi-automatic rifle....." Soldier: "Look, you ain't sellin it to me, you're only showing me how it works."

ARJJ Rifleman Joined Sep 2006 Posts 4625 EE 100% (59) MS, USA	Posted: 12/24/2010 6:04:59 PM EDT [#25] Thanks for the link Dog1!
	STOP RESISTING! fla556guy: "When you have a shit-hole the answer is to flush it as fast as possible, not bathe in the shit."

Dog1 U.S. Rifle, Caliber .30, M1 Joined May 2001 Posts 23654 EE 100% (488) IN, USA	Posted: 12/24/2010 6:12:50 PM EDT [#26] Originally Posted By ARJJ: Thanks for the link Dog1! Not a prob..They are a fantastic place to deal with. Super fast shipping.
	Hansan: "This is a .30 caliber, gas operated, clip fed, semi-automatic rifle....." Soldier: "Look, you ain't sellin it to me, you're only showing me how it works."

bb2007 Member Joined Apr 2007 Posts 1720 EE 100% (251) NV, USA	Posted: 12/26/2010 12:03:44 AM EDT [#27] So...does this also apply to the Pro (5") series? I am thinking of picking up a Pro, and if I can pick up a .40 and just swap out the barrel, then that would be awesome.

Magsz18 Joined Mar 2005 Posts 669 EE 100% (90) FL, USA	Posted: 12/26/2010 2:18:15 AM EDT [#28] Whats the deal with your 9mm barrel behind the chamber/hood area. It looks significantly different than the .40 barrel. Every single 9mm gun that i have looks like your .40 barrel, not the 9mm. Very strange, did they just recently change the design?

Dog1 U.S. Rifle, Caliber .30, M1 Joined May 2001 Posts 23689 EE 100% (488) IN, USA	Posted: 12/26/2010 9:47:50 AM EDT [#29] Originally Posted By bb2007: So...does this also apply to the Pro (5") series? I am thinking of picking up a Pro, and if I can pick up a .40 and just swap out the barrel, then that would be awesome. I cannot speak for the Pro, as I do not have one. All I can say is that you could do what I did and try it.
	Hansan: "This is a .30 caliber, gas operated, clip fed, semi-automatic rifle....." Soldier: "Look, you ain't sellin it to me, you're only showing me how it works."

Dog1

U.S. Rifle, Caliber .30, M1

Joined May 2001
Posts 23690
EE 100% (488)

IN, USA

Posted: 12/26/2010 9:49:22 AM EDT

[Last Edit: Dog1] [#30]

Originally Posted By Magsz18:
Whats the deal with your 9mm barrel behind the chamber/hood area.

It looks significantly different than the .40 barrel. Every single 9mm gun that i have looks like your .40 barrel, not the 9mm.

Very strange, did they just recently change the design?

Are you referring to in front, at the milled flat spot?

Could be a design change.

It still locks up tight.

Hansan: "This is a .30 caliber, gas operated, clip fed, semi-automatic rifle....."
Soldier: "Look, you ain't sellin it to me, you're only showing me how it works."

jtl0101 Member Joined May 2008 Posts 109 EE 100% (16) AR, USA	Posted: 12/26/2010 3:55:16 PM EDT [#31] I got my 9mm barrel for my .40 for Christmas and had bought some 9mm mags a month ago. I had heard that the 9mm barrel would fit the .40 on other threads, so I am glad someone actually posted some good information. It might be a couple weeks but once I get out to the range I will let you guys know if I have any issues.

ARJJ

Rifleman

Joined Sep 2006
Posts 4652
EE 100% (59)

MS, USA

Posted: 12/26/2010 5:37:11 PM EDT

[#32]

Originally Posted By jtl0101:
I got my 9mm barrel for my .40 for Christmas and had bought some 9mm mags a month ago. I had heard that the 9mm barrel would fit the .40 on other threads, so I am glad someone actually posted some good information. It might be a couple weeks but once I get out to the range I will let you guys know if I have any issues.

Please do! I'm seriously kicking around the idea, myself. For about $250, I can have the barrel, several 9mm mags, and a case or so of cheap blasting ammo. I've been thinking about trading my .40s for 9mms, anyway, solely due to ammo cost. I'm trying to get out and shoot more often (at least once if not twice a month), and I've found I can basically get 3 boxes of 9mm for the price of two boxes of .40. I also have a .45 M&P to feed, as well, and .45 has gotten outrageous.

STOP RESISTING!

fla556guy: "When you have a shit-hole the answer is to flush it as fast as possible, not bathe in the shit."

Dog1 U.S. Rifle, Caliber .30, M1 Joined May 2001 Posts 23707 EE 100% (488) IN, USA	Posted: 12/26/2010 6:31:17 PM EDT [#33] As soon as the kids go back to school, I will get to the indoor range and test out my 9mm barrel.
	Hansan: "This is a .30 caliber, gas operated, clip fed, semi-automatic rifle....." Soldier: "Look, you ain't sellin it to me, you're only showing me how it works."

badkarmaiii Those who can't DO, teach... Joined Feb 2009 Posts 1381 EE 0% (0) NM, USA	Posted: 12/26/2010 7:23:48 PM EDT [Last Edit: badkarmaiii] [#34] I have a Pro Series 9mm. What do you guys want me to measure?
	Instructor and M&P & Glock Armorer, Personal Security Consulting: www.traintoprotect.com When seconds count, the police are only minutes away. Train to protect yourself!

Magsz18

Joined Mar 2005
Posts 670
EE 100% (90)

FL, USA

Posted: 12/26/2010 9:57:09 PM EDT

[#35]

Originally Posted By Dog1:

Originally Posted By Magsz18:
Whats the deal with your 9mm barrel behind the chamber/hood area.

It looks significantly different than the .40 barrel. Every single 9mm gun that i have looks like your .40 barrel, not the 9mm.

Very strange, did they just recently change the design?

Are you referring to in front, at the milled flat spot?

Could be a design change.

It still locks up tight.

Im talking about the point right in front of the barrel hood facing the muzzle crown. That area is VASTLY different from my 9mm guns as my 9mm guns look like your .40 in that area.

WEIRD!

Dog1

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Joined May 2001
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EE 100% (488)

IN, USA

Posted: 12/26/2010 10:17:11 PM EDT

[Last Edit: Dog1] [#36]

Originally Posted By Magsz18:

Originally Posted By Dog1:

Originally Posted By Magsz18:
Whats the deal with your 9mm barrel behind the chamber/hood area.

It looks significantly different than the .40 barrel. Every single 9mm gun that i have looks like your .40 barrel, not the 9mm.

Very strange, did they just recently change the design?

Are you referring to in front, at the milled flat spot?

Could be a design change.

It still locks up tight.

Im talking about the point right in front of the barrel hood facing the muzzle crown. That area is VASTLY different from my 9mm guns as my 9mm guns look like your .40 in that area.

WEIRD!

Ok, that's in front of the hood.

Yea I know it's different than my 40 and every other 9mm I have seen too...but it locks up tight.

I wonder if the new barrels are eliminating that extra machining on that part of the barrel, to save costs and that S&W found it was not needed?

Here is what, I think is, an older barrel-

The top one is my new barrel from Brownell's, the bottom is my 40 barrel-

Does anyone have a 9mm barrel like mine, in their M&P?

Hansan: "This is a .30 caliber, gas operated, clip fed, semi-automatic rifle....."
Soldier: "Look, you ain't sellin it to me, you're only showing me how it works."

badkarmaiii Those who can't DO, teach... Joined Feb 2009 Posts 1387 EE 0% (0) NM, USA	Posted: 12/26/2010 10:33:55 PM EDT [Last Edit: badkarmaiii] [#37] My 9mm Pro Series, manufactured 11/11/2010, has that "thick spot" in front of the breech block... ETA: Correct date.
	Instructor and M&P & Glock Armorer, Personal Security Consulting: www.traintoprotect.com When seconds count, the police are only minutes away. Train to protect yourself!

Dog1 U.S. Rifle, Caliber .30, M1 Joined May 2001 Posts 23713 EE 100% (488) IN, USA	Posted: 12/26/2010 10:37:45 PM EDT [#38] Originally Posted By badkarmaiii: My 9mm Pro Series, manufactured 11/11/2010, has that "thick spot" in front of the breech block... ETA: Correct date. I think S&W removed a machining step to cut costs.
	Hansan: "This is a .30 caliber, gas operated, clip fed, semi-automatic rifle....." Soldier: "Look, you ain't sellin it to me, you're only showing me how it works."

jtl0101

Member

Joined May 2008
Posts 113
EE 100% (16)

AR, USA

Posted: 12/31/2010 3:40:50 PM EDT

[#39]

I am posting my after action report of trying out my 9mm barrel in my .40 full size M&P.

I initially shot 30 rounds of .40 ammunition in my original barrel just to make sure the gun was operating properly. Next I changed out the barrel, dug through the bag, and realized I forgot my 9mm magazines at home. After some thought and remembering this thread, I decided to load up my .40 mags with 9mm ammunition and give it a try. I was pretty hesitant at first, but I manually cycled a mag through the gun and then decided to start shooting after that went smoothly. I shot 50 rounds of Independence brass cased and then 50 rounds of brown bear. I had one stove pipe on the brown bear, but other than that it was flawless. The last round would not cycle with the .40 mags,but that was expected by the posts above me. I consider myself a beginner shooter and was really surprised how much more accurately I can shoot 9mm over .40. I now wish I would have just bought a 9mm to begin with. Oh well, now I can shoot two calibers. I hope this helps others.

Dog1 U.S. Rifle, Caliber .30, M1 Joined May 2001 Posts 23799 EE 100% (488) IN, USA	Posted: 12/31/2010 5:31:31 PM EDT [#40] I got my 9mm mags Wednesday..I will heading to the indoor range on Monday to do a controlled test.
	Hansan: "This is a .30 caliber, gas operated, clip fed, semi-automatic rifle....." Soldier: "Look, you ain't sellin it to me, you're only showing me how it works."

Dog1 U.S. Rifle, Caliber .30, M1 Joined May 2001 Posts 23841 EE 100% (488) IN, USA	Posted: 1/3/2011 12:51:01 PM EDT [#41] Range test at the bottom of the OP.
	Hansan: "This is a .30 caliber, gas operated, clip fed, semi-automatic rifle....." Soldier: "Look, you ain't sellin it to me, you're only showing me how it works."

GeorgiaBII Joined Jan 2006 Posts 13155 EE 100% (7) GA, USA	Posted: 1/3/2011 12:54:55 PM EDT [#42] Why won't this work 9 to 40?

PreachermanMATT No King But Jesus Joined Jul 2008 Posts 3398 EE 100% (32) KY, USA	Posted: 1/3/2011 2:04:45 PM EDT [#43] Originally Posted By GeorgiaBII: Why won't this work 9 to 40? inquiring minds and all that
	BCM uppers turn all projectiles into magical laser guided angels of death and destruction. --87GN

Dog1

U.S. Rifle, Caliber .30, M1

Joined May 2001
Posts 23847
EE 100% (488)

IN, USA

Posted: 1/3/2011 7:03:26 PM EDT

[Last Edit: Dog1] [#44]

Originally Posted By PreachermanMATT:

Originally Posted By GeorgiaBII:
Why won't this work 9 to 40?

inquiring minds and all that

According to-

Originally Posted By dirtyone04:
http://www.ar15.com/forums/topic.html?b=5&f=16&t=101824
This is a post I had a few days ago. Same topic.
I did the same thing to my M&P 40c. I did all the measurements and then bought the 9c barrell from brownells as well. It doesn't work the other way around, though. You can't put a 40 barrell in a 9. Has to do with the ramping at the front of the chamber on the 40. I did have the 9 mags to test it and it ran without a hitch

Hansan: "This is a .30 caliber, gas operated, clip fed, semi-automatic rifle....."
Soldier: "Look, you ain't sellin it to me, you're only showing me how it works."

badkarmaiii Those who can't DO, teach... Joined Feb 2009 Posts 1439 EE 0% (0) NM, USA	Posted: 1/3/2011 9:14:59 PM EDT [#45] In my experience, the limiting factor is the width of the barrel hood, the part that protrudes to the rear and engages the breechface cut in the slide. The .40's is wider so .40 can be converted to 9mm but not the other way around.
	Instructor and M&P & Glock Armorer, Personal Security Consulting: www.traintoprotect.com When seconds count, the police are only minutes away. Train to protect yourself!

17 Joined Jul 2005 Posts 17 EE 100% (133) CT, USA	Posted: 1/4/2011 5:39:26 AM EDT [#46] OK stupid me just asked about the reliability of convertion kits and BAM scroll down and find this thread. Damn i love this site....

WIZZO_ARAKM14

Woods rider

Joined Dec 2004
Posts 11223
EE 100% (73)

IN, USA

Posted: 1/4/2011 9:08:18 AM EDT

[#47]

Probably doesn't help much as you guys have already pretty much pinned down the answer, but here goes.

I just picked up my new M&P9 w/thumb safety yesterday. Upon stripping it, it has the same type of machining as your .40 barrel, Dog1. Course, the 2 test fire cases are dated 4-1-2010, so it's been sitting at some distributor for a while.

Thought I'd chime in!

Posted Via AR15.Com Mobile

1911 junkie

It's time for an 'ol fashioned Hippie Ass whompin'- Chief Wiggum

PreachermanMATT

No King But Jesus

Joined Jul 2008
Posts 3403
EE 100% (32)

KY, USA

Posted: 1/4/2011 9:17:27 AM EDT

[#48]

Originally Posted By WIZZO_ARAKM14:
Probably doesn't help much as you guys have already pretty much pinned down the answer, but here goes.

I just picked up my new M&P9 w/thumb safety yesterday. Upon stripping it, it has the same type of machining as your .40 barrel, Dog1. Course, the 2 test fire cases are dated 4-1-2010, so it's been sitting at some distributor for a while.

Thought I'd chime in!

Posted Via AR15.Com Mobile

do you have a .40 barrel accessable to try?

BCM uppers turn all projectiles into magical laser guided angels of death and destruction. --87GN

WIZZO_ARAKM14 Woods rider Joined Dec 2004 Posts 11229 EE 100% (73) IN, USA	Posted: 1/4/2011 9:00:43 PM EDT [#49] Negatory
	1911 junkie It's time for an 'ol fashioned Hippie Ass whompin'- Chief Wiggum

chris65 Member Joined Apr 2003 Posts 2343 EE 100% (3) IL, USA	Posted: 1/4/2011 9:34:49 PM EDT [Last Edit: chris65] [#50] Good post OP. Where is the brass landing 40 vs 9? I saw the one post where a 9mm stovepipe jam occured and in that case, it may be handy to have a spare recoil spring with one coil cut-off to allow more slide velocity. Generally, I think 40 slides weigh more than 9s.
	"A man with one AR is like a man with one arm." -me (pun intended)

9mm M&P barrel in a .40 S&W-a photo comparison-UPDATE IN OP-Range test (Page 1 of 7)

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